Its surface shows channel openings made of 12-membered rings (7.0 x 6.5 [Angstrom]), 8-membered rings (2.6 x 5.7 [Angstrom]), and smaller 4-membered rings.
Metal-catalyzed reactions of heterocycles (3- and 4-membered rings) with heterocumulenes is a novel approach developed by Alper and coworkers for the preparation of interesting cycloaddition products.